Bender



June 26, 1934. H ABRA SON Er A 1,964,550

BENDER Filed July 7, 1930 3 Sheets-Sheet l June 26, 1934. J. H. ABRAMSONET AL 1,964,550

BENDER Filed July 7, 1930 v 3 Sheets-Sheet 2 Q Q7 W M; K g

June 26, 1934.

3 Sheds-Sheet 3 Patented June 26, 1934 BENDEB John Herbert Abramson andEdwin C. Swanson,

Rockford, Ill., assignors to Greenlee Bros. 6':

00., Rockford, 111., a corporation of Illinois I Application July 7,1930, Serial No. 466,094 14 Claims. (01. 153-38) Our invention relatesto benders for bending pipes, rods, bars and the like, and has specialreference to a portable hydraulic bending device more particularly forthe bending of metal conduits employed in electric wiring activities.

In'the past it has been possible to bend metal conduits only with thegreatest difiiculty when the operator desires to do so at the point ofuse. Where bending is desired it may, of course, be accomplished at thefactory by the usual hot bending methods, or through the customary largecold bending machines, but during the installation of this conduit it ismany times desirable for the workman to bend the metal. Because of theusual thin wall of this pipe it has a marked tendency to flatten outwhen bent by improper methods. 7

We have, therefore, aimed to provide an improved pipe bending devicewhich may be carried about by the workman from place to place withrelative ease.

Another object of our invention is the provi-' sion of a portable pipebending device which may be operated with a minimum amount of physicaleiiort on the part of the workman.

A further object of the invention is the provision of a portable pipebender wherein the bending movement takes place parallel to thesupporting surface whereby any length of pipe may be bent and whereinmeans are provided on the top of the bender for actuating the same.

We have also aimed to provide a portable pipe bending device having ahydraulically operated piston and a small fluid pump adapted to beactuated by a workman to provide hydrostatic pressure for operating thepiston in its bending stroke.

A further object of the invention is to provide a hydraulic pipe benderhaving simple and eflicient means for relieving the pressure andpermitting the fiow of liquid from the cylinder chamber.

Another object of the invention is the provision of a pipe bender havingan improved injector for transferring the liquid from the well to thecylinder.

A still further object of the invention is the provision of a combinedinjector and pressure releasing mechanism.

We have still further aimed to provide a. pipe bender having improvedmeans for holding the pipe at the points between which the bend is to bemade.

A still further object of the invention is the provision of improvedmeans for actuating the piston of the fluid injector.

Other objects and attendant advantages will become apparent to thoseskilled in the art from the following description and the accompanyingdrawings, in which- Figure 1 is a top view of our improved pipe bendershowing a'section of pipe in a position to be bent and in dotted linesthe relative position of the parts after bending has occurred.

Fig. 2 is a vertical secti bender showing the piston tion.

Fig. 3 is a section on showing the injector in discharge fluid from thewell.

Fig. 4 is a section showing the injector Fig. 5 is a section Fig. 6 is asection blocks; and

Fig. 7 is a section thr on through our improved in its retracted positheline 3-3 of Fig. 1 section in a position to cylinder chamber to the onthe line 3-3 of Fig. 1

its pumping position.

the line 55 of Fig. 3.

through one of the holding ough a holding block at right angles to thatshownin Fig. 6.

The invention consists, in a. general way, of a body lO having two pairof links designated by 11 and 12 and by 13 peering on the drawings and14,

the link 14 not apbut occupying the same relation to link 13 as link 12occupies with respect to link 11, the two their outer ends by a pair of20, which also serve to 0 pair being connected at cross bars 15 andHolding blocks designated generally by 17 and 18, are pivotallysupported upon bolts 19 and onnect the links of each pair at their outerend and receive opposite ends of the cross bars 15 and 17 and 18 areadapted to 16. The holding blocks cooperate with a shoe 21 to receive apipe 22 therebetween which is arranged to be bent through a desiredcurvature.

The shoe 21 is supported on the outer end of a piston 23 adapted to beprojected from the end of the body 10 by operation of an injector lever,designated generally by the numeral 24, positioned upon the body 10.Thus as for example the pipe a pipe or bar to be bent,

22, is positioned between the holding blocks 17 and 18 and the shoe 21with the links 11 and 13 on the links 12 and 14 on Operation of theinjector one side of the pipe and the other side thereon, lever 24causes the piston 23 to move outward forcing the shoe 21 against thepipe whereby it is between the blocks 17 a bent through an angle nd 18,the blocks rotating through an angle during this bending movement, allas shown in When the piston 23 is 10 the pipe 22 in its bent frombetween the links.

dotted lines in Fig. l. retracted into the .body condition may be movedlower side of the body 10.

" 25 and 26 passing and ha we the holding block 1'1 Special attention isdirected to the fact that the parts are so arranged that the bendingoperation occurs in a plane parallel to the support and in closeproximity thereto.

We will now proceed to describe the invention more in detail, likenumerals being employed to designate like parts throughout the drawings.The inner ends of the links 11, 12, 13 and 14 are pivotally secured tothe body 10 through pins through the body 10, the body being somewhatenlarged at 2'1 and 28 near the piston end 29 to lend the structuresufllcient strength to withstand the stress imposed on the pins 25 and26. The end of the link 11 is pro.- vided with an opening to pivotallyreceive the pin 25 and is positioned on the pin at of the body 10through a cotter pin 30, while the link 12 is positioned in like manneron the Similarly links 13 and 14 are positioned on opposite ends of thepin 26 at opposite sides of the body 10 by means of cotter pins 31. Thusthe links 11 and-12 and the links 13 and'14 project outward from thebody 10, the links of each pair lying substantially parallel and inspaced relation. The outer ends of the links 11 and 12 are connected bythe pin 19 interposed therebe-' tween. In like manner the outer ends ofthe links 13 and 14 are connected by the pin 20 and have the holdingblock 18 interposed therebetweenon pin 20. Cotter pins 32 and 33 serveto maintain the links on the pins. Cross bars 15 and 16 are supported onthe pins 19 and at each end and are positioned on opposite sides of theholding blocks 1'1 and 18. The blocks 1'1 and 18 being rotatablypositioned upon the pins 19 and 20 are free to rotate about the pins asthe shoe 21 moves the center point of the pipe 22 inward.

In order to prevent any substantial amount of flattening of the pipe 22we have found it advisable to provide a plurality of shoes 21 havingdifferent curvatures on the working face 34 thereof to correspond withdifferent sized pipes. In like manner the holding blocks 1'1 and 18 areeach provided with a plurality of working faces 35, 36, 3'1 and 38, asclearly shown in Figs. 6 and '1. The holding blocks being rotatable uponthe pins, any one of the working 'faces thereof may be brought intooperative relation with the pipe. The working faces are each positionedat such a distance openings 11a that the center of the openingregardless of the size. In the particular instance shown the workingface 35 is made for use with three inch pipe, the working face 36 withtwo and one-half inch pipe, the face 3'1 with two inch pipe and the face38 with one and one-half inch pipe. We have found through experimentthat in most cases the working face 38, designed particularly for oneand one-half inch pipe, may be satisfactorily used in bendin pipesubstantially smaller, as, for example,- three-fourth inch pipe, sincethe wall of these smaller pipes It will be may be provided forcooperation ofpipe and we do not intend to limit ourselves to theparticular sizes mentioned. In thisparticular instance four shoes 21 areprovided to co-' operate with the working faces on the holding blocksinbending four different sized pipes.

A series of holes 40 in the links 11 and 12 and holes 41 in links 13 and14 are provided near the outer ends thereof to receive the pins 19 and20 the upper side' is relatively 'surface of the when pipes of smallerdiameter are being bent. A series of holes 42 at one end and 43 at theother end of the cross bars 15 and 16 are provided to be used inconjunction with the holes 40 and 41 to receive the pins 19 and 20whereby the radius of the arc to be bent in the tube between the holdingblocks Hand 18 may be altered. This is desirable in that it permits ashorter stroke of the shoe 21 than would otherwise be possible, since ifthe blocks were employed in the position shown in Fig. l for bendingsmall pipe it would be necessary to project the shoe 21 outwardconsiderably further than shown in order to bend a 90 angle therein.

The portion of the body 10 adjacent to the end 29 is arranged to form acylinder wall 39 to provide a cylinder chamber 44 in which the piston 23is adapted to reciprocate and to closely fit the inner walls thereof.The forward end of the piston is provided with a projection 45 having agroove 46 therein adapted to receive a at screw 4'1 for the purpose ofmaintaining the shoe 21 securely on the end of the piston 23. The rearend of the piston 23 is provided with a leather cup 48 secured theretoby means of a large headed metal screw 49, the upturned edges 50 of thecup being adapted to closely fit the inner surface of the wall 39 of thecylinder chamber 44 to substantially prevent the passage of fluid alongthe interface between the piston 23 and the cylinder wall 39.

The rear end 51 of the body 10 is provided with a well 52 adapted tohold a quantity of fluid for the operation of the piston 23. A removableplate to enclose the end of the body 10 to an injector designated 110generally by 54 presently to be more fully described. A pair of ears 55and 56 are formed integrally on the top of the body' 10 near the end 51thereof and have an injector lever 24 pivotally secured therebetween ona 'pin 58. Cotter pins 59 1 5 in each end of the pin 58 serve to securethe latter in proper position between the ears. An injector plunger 60is adapted to be operated by oscillation of the lever 24 about the pin58, a rdd 61 being threaded into the injector lever 24 to permit easy nomovement thereof by the operator.

The injector lever 24 is provided at its lower end with downwardlyprojecting side walls 62 and 63 adapted to form a recess 64therebetween. Arms 65 and 66 are pivotally secured against the 25 innersurface of the side walls 62 and 63 through pins 6'1 and 68 rotatablysecured therein. The upper ends of the arms 65 and 66 are provided withsuitable openings to support a. shaft 69 passing through the injectorplunger 60. By this ar- 130 rangement the plunger 60 is attached to thelever for the plunger 60.

Referring now toFigs. 3 and 4 the injector 54 includes an injector tube'10 having an inlet openan outlet opening '12. The lower end of theinjector tube '10 is positioned in a cylindrical socket '13 formed onthe upper side of a projection '14 from a wall '15 separating thecylinder chamber 44 from the well 52. The upper end ofthetube'lOissecuredinthewallsofthe body 10 by a bushing '16 threaded tothe body 10 and ar- 5 rangedto bear against a shoulder '17 on the outerinjector tube '10. A stufllng box is formed by the sleeve '18 closelyfitting the plunger 60 and threaded into the bushing '16 whereby to apacking material '19 positioned bethe passageway 88. In

tween the lower end of the sleeve 78 and the upper end of the injectortube 70. This stufling box prevents the escape of fluid from theinjector along the plunger 60. A leather or other packing ring 80 ispositioned within a recess 81 and is adapted to be pressed downward by ashoulder 82 on the outer surface of the injector tube 70 to prevent thepassage of fluid therethrough.

The injectoris adapted to pump fluid from the well 52 through a pipe 83and the inlet 71 by operation of the plunger 60. When the plunger 60 isdrawn upward the fluid will be drawn into the injector tube 70 throughthe inlet'71 against the pressure of a ball 84. When the plunger 60starts its downward movement the ball 84 is pressed firmly over theopening 71 by action of a coil spring 85 bearing against a plug 86, thuspreventing egress of the liquid through the inlet 71. Pressure on thefluid in the tube 71 will cause a ball 87, held in position across anopening 88 by a spring 89, to be unseated permitting the fluid to flowthrough the opening 88 into a lower chamber 90 within which the ball 87and the spring 89 are secured by means of a threaded plug 91 screwedinto the lower end of the injector tube 70. From the chamber 90 the oilmoves through the outlet 72 into a passageway 92 connecting the chamber90 with the cylinder chamber 44. It will be seen that continuedoperation of the injector will remove fluid from the well 52 and pass itinto the cylinder chamber 44. The pressure of the fluid against the endof the piston 23 will cause the piston to move outward along thecylinder. With continued operation of the injector the piston willeventually reach a point at which the fluid in the cylinder chamber may,pass from the cylinder chamber, through an opening 93 in the wallsthereof and a passageway 94, back to the well 52, thereby releasing thepressure against the end of the piston 23. The outward movement of thepiston will be automatically stopped at this point because of thisrelease in pressure. This arrangement prevents accidental displacementof the piston from the end 29 of the body or the accidental breakage ofany parts arranged to prevent excessive movement thereof.

A circular depression 95 extends completely around the inner surface ofthe cylinder wall and serves to collect any of the fluid which may havebeen forced by the cup 50 along the interface between the cylinder walland the piston 23. A passageway 96 permits this oil to be returned tothe passageway 94 and conducted back to the system.

The passageway 94 extends along the bottom side of the body 10, betweenthe openings 93 and 96 and the well 52, and, since the device isemployed in a horizontal position, will normally be filled with fluidand the well. For this reasonthe lower end of the pipe 83 is arranged toextend into this passageway as shown in Figures 2, 3-, and 4, so that amajor portion of the fluid may be removed from the well by action of theinjector.

In order to relieve the pressure in the cylinder chamber 44 with thepiston at any point short of the opening 93 and to permit the fluid tobe returned from the cylinder chamber-to the well 52 we have arranged topermit the plunger 60 to be moved downward beyond its normal strokewhereby the lower end thereof strikes the ball 84 causing it to be movedaway from the inlet 71 against the upper end of the ball 87 and to movethe ball 87 downward slightly thereby opening this manner-the fluid inwill be the lowest point in 3 the cylinder chamber 44 may move throughthe passageway 92, the chamber 90, the opening 88 and out through theinlet 71. This movement of fluid may be caused by manually grasping theshoe 21 and pushing the piston 23 inward, the movement beingaccomplished with but a small amount of effort. When the downward by thelower end of the plunger 80 the spring 85 will be slightly distorted andthe parts will occupy substantially the position shownin Fig. 3, thenormal-positions of the parts being shown in Fig. 4. In order to limitthe normal downward movement of the plunger 60 during the operation ofthe injector we have provided a stop 98 pivotally secured to the top ofthe body 10 through a pin 99 and arranged to be held in the positionshown in Fig. 2 during the normal pumping operation by a spring 100.When fluid is desired to be released from the cylinder the stop 98 ismoved against the spring to the position shown in Fig. 3 whereby theinjector lever 24 may be moved downward beyond its normal stroke,thereby moving the plunger 60 against the ball 84.

A plug 101 is inserted through the wall of the body 10 into the well 52and is provided with a small opening 102 against which a ball 103 issecurely held by a spring 104. The arrangement is such as to permit airto enter the well 52 when fluid is being pumped therefrom into thecylinder chamber '44 but to prevent the passage of fluid out through theopening 102. The arrangement thus permits the relief of any decrease orincrease in pressure which may be formed in the well 52 by the movementof fluid.

In assembling the device the injector 54 is positioned by inserting itthrough the open end of the body 10. After the injector has beensuitably secured in its position, as will be obvious from the drawings,the well 52 is completely filled with a suitable fluid, such for exampleas oil, and the end 53 is secured over the well 52.

The advantages of our improved construction may be readily apparent tothose skilled in the art. We have provided a machine adapted to be usedin a horizontal position wherebyany-dep sired length of pipe may bebent. We have provided holding blocks having a plurality of bearingsurfaces thereon of different curvature adapted to be employed inbending pipe of dif- 25 the same means, no separate releasing meansbeing required. The means employed for releasing the fluid isexceedingly simple and convenient of 3 operation and may be manufacturedat relatively small cost.

We have provided an exceedingly compact and simple device which may becarried about by the operator from place to place.

We have provided a device wherein no stufling box is needed at theforward end of the cylinder, in other words the piston itself acts as a.connecting rod to the shoe 21 whereby maximum strength is had and astufling box is eliminated.

Another marked advantage resulting from our improved constructionand-arrangement is the greater ease with which the pipe may be bent. Thepipe is bent in a position close to the floor and in a directionparallel thereto. Because of this ends of the pipe are merely movedalong the floor during the bending operation. Since the device restsdirectly on the floor and the injector handle is positioned on the topof the body, the operation thereof is easily accomplished by theoperator standing in a position over the device.

a cylinder, means spaced points, a piston adapted said pipe between saidpoints, and means for urging said piston against said pipe in bendingmovements including means comprising an injector system within said bodyand a handle outside said body for injecting fluid into said cylinder toproject said piston, and means operable to permit fluid to flow out ofsaid cylinder whereby said piston may be retracted.

2. The combination in a hydraulic device of the character described, ofmeans for holding a pipe at spaced points, a shoe adapted to bearagainst said pipe between said points, and means for urging said shoeagainst said pipe in bending and return movements including, a bodyhaving a hydraulic cylinder, a piston in said cylinder arranged to beprojected therefrom, means for automatically relieving the pressure onsaid piston to limit the outward movement thereof, means for injectingfluid into said cylinder to project said piston, and means operable topermit fluid to flow out of said cylinder whereby said piston may beretracted.

3. The combination in a hydraulic device of the character described, ofmeans for holding a pipe 45 at spaced points, a shoe adapted to bearagainst urging said shoe against said pipe in bending and returnmovement including, a body having a hydraulic cylinder, a piston inranged to be projected therefrom, means for injecting fluid into saidcylinder toproject said piston, means arranged to automatically causethe flow of fluid out of said cylinder when said piston is projected toa predetermined point, 'whereby to relieve the pressure therein and stopthe movement of said piston, and means within said body operable topermit fluid to flow out of said cylinder whereby said piston may beretracted. v

4. The combination in a portable pipe bender of the character describedadapted to bend a pipe horizontally, of means for holding a pipe atspaced points, a shoe adapted to bear against said pipe between saidpoints, and means for urging said shoe against said pipe inhorizontal'bending and return movements including, a body having ahorizontal cylinder, a piston in said cylinder arto be projectedtherefrom, an injector radially positioned within said body forinjecting fluid into said cylinder to project said piston, a manuallyoperable lever on the top of said body arranged to be reciprocatedvertically to operate said injector, and means operable to permit fluidto flow out of said cylinder whereby said piston I ll maybe retracted.

5. The combination in a hydraulic device of the character described, ofa body, a piston arranged to be retracted or projected from one end ofsaid body, a shoe on the outer end of said pis-' ton adapted to fit anobject to be bent, holding blocks, links connected to said body andarranged to support said holding blocks in any of a plurality of fixeddistances from said body, whereby an object to be bent may be interposedbetween said shoe and said blocks, links for connecting and spacing saidblocks in any of a plurality of fixed distances apart, said linksproviding means whereby bends of. different curvature may be produced,and means for projecting said cylinder whereby said said object betweensaid blocks to laterally displace said object therebetween and producean arcuate bend therein.

6. The combination in a portable pipe bender of the character described,adapted to bend pipe horizontally, of means for holding a pipe at spacedpoints a shoe adapted to bear against said pipe between said points, andmeans for urging said shoe against said pipe in bending and returnmovements including, a body having a well and a horizontal cylinder, apiston in said cylinder arranged to be projected therefrom, and aninjector fixedly positioned within saidwell arranged to inject fluidfrom said well into said cylinder to project said piston and to permitfluid to flow from said cylinder into said well whereby said .piston maybe retracted.

7. The combination in a hydraulic device of the character described, ofmeans for holding a pipe at spaced points, and means for exerting abending force against said pipe between said points including a bodyhaving a well and a hydraulic cylinder, a piston in said cylinderarranged to be projected in bending movement, an injector within saidwell arranged to move fluid from said well into said cylinder to projectsaid piston, a handle arranged to operate said injectorrand meansoperable by said handle to provide an opening between said cylinder andsaid well to permit fluid to flow from the former to the latter wherebysaid piston may be retracted.

8. A holding block having a centrally disposed opening for pivotallysupporting the same and a plurality of faces of different curvatureadapted to support cylindrical bodies of different sizes being bent,each of said faces being placed a distance from said opening such thatthe centers of .curvature thereof will be substantially the samedistance from said opening.

9. In a pipe bending machine a body, a piston having means for exertinga bending force, and means for operating the same including an injectorhandle for reciprocating an injector plunger, having downwardlyprojecting side walls arranged to form a recess therein, means forhingedly supporting said handle on said body, a shaft pivotally secured,in the upper end of said plunger transversely of said cavity, and a pairof links pivotally secured at their lower ends to said side walls and attheir upper ends to said shaft. arranged to reciprocate said plungerwhen said handle is moved about its pivotal support.

10. In combination in a portable hydraulic device of the characterdescribed, a body having a cylinder lying in a plane parallel to thefloor, means thereon for holding a pipe at spaced points in closeproximity to the floor, a piston in said cylinder adapted to bearagainst said pipe between said points, and means for urging said pistonagainst said pipe in bending movements whereby to bend said pipe in adirection parallel with the floor including an injector positionedwithin said body to be operated from the upper side of said bodyforconvenient operation by the user in a standing position over thedevice.

11. -.The combination in a portable bender of a body having a cylinder,apiston in said cylinder and means for projecting said piston to exertpressure on a pipe, a pair of bearing blocks for holding said pipe, andpairs of vertically spaced links connected at one end to opposite sidesofsaid body, each of said links having openings at its outer end torotatably support said bearing blocks.

12. The combination in a portable bender of a body having a cylinder, avpiston in said cylinder and means for projecting said piston to exertpressure on a pipe, a pair of bearing blocks for holding said pipe, andpairs oi vertically spaced links connected at one end to opposite sidesof said body, each of said links having openings at its outer end torotatably support said bearing blocks, and a pair of links connectingthe outer ends of said spaced links to maintain said bearing blocks adesired distance apart.

13. The combination in a hydraulic device 01. the character described,of a horizontal body, a piston arranged to be retracted or projectedfrom said body, jection means including an injector the major portion ofwhich is enclosed within said body and a handle above said body, a shoeon the outer end of said piston adapted to fit a cylindrical object tobe bent, bearing blocks supported on said body on opposite sides of saidshoe arranged to hold said object at the points between which it is tobe bent, whereby said shoe may be forced against said objectintermediate said bearing blocks, by projection of said piston, tolaterally displace said object between said blocks and produce anarcuate bend therein.

14. The combination in a portable hydraulic device of the characterdescribed of a body, adapted to rest horizontally upon the floor tosupport said device, a piston arranged to be retracted or projectedhorizontally from one end of said body, a shoe on the outer end of saidpiston adapted to fit an object to be bent, spaced blocks, linksconnected to said body and arranged to support said blocks beyond theend of said body on each side thereof, whereby an object to be bent maybe interposed between said shoe and said blocks, means for projectingsaid piston, and injection means including a handle manually operableabove said body whereby said shoe is brought into contact with saidobject between said blocks to laterally displace said objecttherebetween and produce an arcuate bend therein;

JOHN HERBERT ABRAMSON. EDWIN C. 'SWANSON.

